Whoops, the auto-spelling correction in my eyes seamlessly transformed the abbreviation - and it might have really been a question about mtf since the concept isn't self-explanatory. But thanks for notifying me :-p

But, actually, I missed the point about the shorter MFD of 20 cm that I just read in the description, vs. 38 cm as stated in the Canon specifications. Thanks for pointing that out!

Let's think about the practical implications. An MFD of 20 cm, with the Canon flange-focal distance of 4.4 cm and a lens that when extended to 70 mm focal length is 12 cm long (DPR's spec is a little longer, I subtracted for the part of the mount that extends behind the flange). So the working distance of the bare lens is ~3.6 cm, and if you put on a Canon EF 25 II extension tube (which is actually 27mm long), your working distance is 0.9 cm, i.e. to get that almost 1:1 magnification, your subject is less than a finger-width from the front element. Yikes! H-IS for longer exposure or not, with the apparent light loss at high reproduction ratios, it's going to be pretty hard to use this lens for macro.

A Kenko 1.4X TC might be better than tubes for a lens like this if you want macro. I'm not recommending it, but putting the objective a fraction of a inch from the subject makes it very difficult to illuminate and easy to get squashed bug on your lens.

As scary as that sounds, those of us coming from the MP-E 65 macro lens at least understand what that entails.

Yeah, but even at 5x on the MP-E 65mm there's a working distance of 4 cm (the bare 24-70/4L IS has less WD). At less than 1 cm of WD, there's not even room to put an MT-24EX on there (the step-down ring, Macrolite adapter, and mount ring would mean you'd only be able to backlight your subject with the twin lite).

That's ok, though - there's a workaround. Imagine it...the 24-70mm f/4L IS as a very convenient, dual purpose walk around lens - general purpose zoom and macro. Made only slightly less convenient by the necessary lighting for macro shooting...

Neuro, talking macro here, could you kindly tell about those wonderful extending arms fit on this MT-24EX ? Been trying hard to find this sort of contraption, but not to avail yet. I sometimes use one of the flashes by hand for back-lighting but when doing macro, I'd prefer to keep my third hand to hold the umbrella

Neuro, talking macro here, could you kindly tell about those wonderful extending arms fit on this MT-24EX ? Been trying hard to find this sort of contraption, but not to avail yet. I sometimes use one of the flashes by hand for back-lighting but when doing macro, I'd prefer to keep my third hand to hold the umbrella

That's a Really Right Stuff flash bracket setup. For the MT-24EX, look in the Off-Camera Flash section, FR-87-QR bracket, a second B-87-QRFM mount, and a pair of FA-QREX2 extenders. RRS gear is exceptionally high quality, but not cheap. The setup above will run you about the same as the current price MT-24EX itself, a little more if you have to add the Arca-Swiss-type plate to mount the bracket (a lens plate for a collared lens like the 180L, or multipurpose rail w/ clamp to convert the 'sideways' body plate/L-bracket to a fore-aft plate for the flash bracket).

I'll be ordering the above setup, plus a B-150B macro rail, in the next few days.

That's a Really Right Stuff flash bracket setup. For the MT-24EX, look in the Off-Camera Flash section, FR-87-QR bracket, a second B-87-QRFM mount, and a pair of FA-QREX2 extenders. RRS gear is exceptionally high quality, but not cheap. The setup above will run you about the same as the current price MT-24EX itself, a little more if you have to add the Arca-Swiss-type plate to mount the bracket (a lens plate for a collared lens like the 180L, or multipurpose rail w/ clamp to convert the 'sideways' body plate/L-bracket to a fore-aft plate for the flash bracket).

I'll be ordering the above setup, plus a B-150B macro rail, in the next few days.

Terrific ! Thanks for this invaluable info. Price will be secondary issue compared to how, in SEA, I'm going to be able to put my hand (the remaining one) on this incredible stuff.

I myself fail completely to see the market for this lens. Sure, if they are going to 'force it down your throat' as a Kit lens, maybe... but lets see who would choose this lens:- For versatility, the 24-105 has the same widest aperture, and considerably longer reach.- For speed, you have any of the 24-70 2.8 options (including the mI) in Canon and even other brands.- For those 'amateurs' looking for a good lens, they are probably on an APS-C sensor, and therefore have MUCH better and less expensive choices like the 17-55 f2.8 IS .

Again, if it would be on the $1K range... then I can see this as a good lens which several people will chose: newer better optics vs. the extra 35mm reach of the 24-105 could be interesting, but not paying TWICE as much!!! Never! As mentioned, for APS-C sensors, the shorter focal range zooms are actually more in the 'normal' range, the 17-40 included, which sells for about $700!.

So this lens is certainly best for FF cameras, and those having them will either pay the extra for the 2.8 versions or go for primes. I really only see them ditching the 24-105 (which would be purely from a marketing point of view as it is a fantastic lens! they would really be ill-treating customers if they dropped it!) and forcing this new 24-70 f4 as a kit lens.

So, IMHO, I see a purely commercial move that will involve some very 'wrong' (from the customer point of view) decisions. I see no other 'great' scenario for this lens. The 17-40 is better for most landscapers and crop sensors, the 24-70 mI, mII and Tamron are better choices for professionals and the 24-105 is a better choice for an all around lens.

I really fail to see this lenses purpose as well as others (and I don't think the 24-70 mII is a great success from a technological point of view, its a great success commercially because people just *have* to have the latest and priciest, but I believe, as others, that Canon 'failed' with that lens - which doesn't mean people are not buying it... perhaps we are talking about different types of 'fail' here - )

- For those 'amateurs' looking for a good lens, they are probably on an APS-C sensor, and therefore have MUCH better and less expensive choices like the 17-55 f2.8 IS.

Since Canon obviously is not able to release something better than the very iso-limited 18mp sensor (i.e. everything above iso 800 is crappy) it makes sense even for an amateur to get ff. When the 6d price drops it won't be far away from the 7d which some people only get for the sturdy build & sealing and not for the af or fps.

I really fail to see this lenses purpose as well as others (and I don't think the 24-70 mII is a great success from a technological point of view, its a great success commercially because people just *have* to have the latest and priciest, but I believe, as others, that Canon 'failed' with that lens - which doesn't mean people are not buying it... perhaps we are talking about different types of 'fail' here - )

Rafa.

Look, if I had to have only one lens in my bag, it would probably be the 24-105. Don't want to be controversial here, but from what I understand, this lens is usually considered good but not really stellar. If the MTF (sorry for misspelling...) charts deliver what they promise, this 24-70/4 should be markedly better - at least in sharpness - than the 24-105 and close to 24-70/II.

I am rather a prime shooter. Yet sometimes I am a bit annoyed at having to swap lenses all the time. I miss a general photo zoom in this range for happy-go-lucky shooting. I won't go for the 24-105. I think a bit far from what I am used with primes, I guess. I'm still holding going for the 24-70/II as I still have to swallow the +700/800 bucks for new 82mm filters.

So, when this 24-70/4 comes in with IS, 0.7x macro, 77mm thread and promising MTF charts, I think it looks like a sound package. Well, to me at least.

...Since Canon obviously is not able to release something better than the very iso-limited 18mp sensor (i.e. everything above iso 800 is crappy) it makes sense even for an amateur to get ff...

Well, I disagree with you apparently in every front . I have a T2i and can count on ISO1600 for everything, even big and important shots, and I can count on ISO3200 for semi-decent results (if I nail the exposure... underexpose a 1/3th of a stop and you are dead!), but I might concede to the fact that we are limited in ISO.

But to claim that amateurs can go for a FF is really a bold statement. Most amateurs (or even some budget-limited half-time professionals like me) simply cannot afford FF, both in camera and glass. So crop sensor + good lenses for us is quite a different approach all togther.

So, while I see where your reasoning is coming from, its not really true for a lot of us who simply cannot afford a $2500 camera and another $2500 lens!

...Look, if I had to have only one lens in my bag, it would probably be the 24-105. Don't want to be controversial here, but from what I understand, this lens is usually considered good but not really stellar. If the MTF (sorry for misspelling...) charts deliver what they promise, this 24-70/4 should be markedly better - at least in sharpness - than the 24-105 and close to 24-70/II...

Glad to see the perspective of the actual buyers this lens might be targeted to (I really failed to see cases like yours). My only note on your decision making process is that you are basing it on charts. When we saw the 24-70 mII charts we all thought: Ok, nothing will touch this lens... but on-the-field experiences have shown that it is good, but not that much better than the mI (certainly NOT $1000 extra!).

So, I'm sure Canon is not about to butcher their own sells of the mII producing a sharpness-matching $1500 lens, they'd have to be crazy! So I believe we can all assume that the f4 would be considerably less good than the f2.8 mII (for the 2.8 to be still a viable choice!). So I believe you'll see marginal (if any) improvements over the 24-105! This is, of course, speculation, I have no hard facts to support this, I'll just have to wait until there is reasonable out on the field samples.

At any rate, I'm glad you see in this your niche lens. Perhaps I really don't know the market at all. Best regards,Rafa.

So, I'm sure Canon is not about to butcher their own sells of the mII producing a sharpness-matching $1500 lens, they'd have to be crazy!

However the 24-70/4 has the latest IS system and near-macro capability, so it's really in a different class than the 24-70/2.8 which are pure event lenses where the IS wouldn't have time to lock anyway - internal competition should be minimal in this case.

When we saw the 24-70 mII charts we all thought: Ok, nothing will touch this lens... but on-the-field experiences have shown that it is good, but not that much better than the mI (certainly NOT $1000 extra!).

How much "worth" $1000 is certainly depends on how deep your pockets are, and the mk2 has better af quality with the 1dx/5d3 af system next to being sharper @f2.8 across the frame.

But as the LensRentals review suggests the mk2 has a more sturdy build that is less prone to decentering when taking a hit - so you have to substract the price of some tours to Canon service from the mk2 price and add it to the mk1.